Vibration damping novel surface structures and methods of making the same

ABSTRACT

A gas turbine or turbine component partially or fully coated with a damping surface layer. The damping surface layer may have a thickness between 0.1 and 2000 microns and may be capable of dissipating vibration or modifying a resonance frequency of the gas turbine or turbine component at ambient room temperatures including operational temperatures greater than 500° F., and the damping surface layer comprises at least one of (a) at least two layers comprising a first layer of at least one hard material and a second layer comprising at least one soft material, (b) a composite comprising a nickel alloy with a heat softenable chemistry, (c) a fine-grained nickel-based superalloy, or (d) a porous metallic coating, a porous metallic and ceramic coating, or a ceramic coating.

BACKGROUND OF THE INVENTION

The present invention generally relates to turbines and generallyrelates to surface structures that damp vibration of turbine components.

Operation of a turbine may subject many of the turbine's components tovibrational stresses. Vibrational stresses may shorten the fatigue lifeof components, thus potentially subjecting them to failure, especiallywhen the components are also subjected to the harsh environment of a gasturbine.

One way to reduce vibrational stresses and extend the life of componentsmay relate to damping the vibration of the component, thus potentiallyaltering vibrational characteristics in such a way to increase itsuseful life. Mechanical damping mechanisms have been used to dampvibration of turbine components. Examples of the mechanical meansinclude a spring-like damper inserted in a rotor structure beneath theairfoil platform, or a damper included at the airfoil tip shroud.

The phenomenon of damping may generally refer to the process ofabsorbing and converting the energy associated with a given oscillationinto a different form of energy. Damping or energy dissipation can becaused by a combination of mechanisms depending on the mechanicalstructure (i.e. structural damping) as well as by a variety ofmechanisms depending on the material's composition and processingconditions (i.e. material damping). All microscopic and macroscopicmechanisms taking place within the volume of a vibrating part andcausing energy dissipation during operation may contribute to materialdamping.

The removed energy may be converted directly into heat or may betransferred to connected structures or ambient media. Micromechanismscausing internal damping in single or multiphase crystalline metallicmaterials may be called internal friction. In structural mechanics, itmay be common to describe a structure in terms of modal parameters. Eachmode corresponds to one degree-of-freedom and is characterized by aresonance frequency, a deformation vector and a modal damping. Thestructural response for a given force input may then be obtained bylinear superposition of all modes. In the context of modalrepresentation, structural damping is expressed in terms of modaldamping values.

The desired properties of high strength, stiffness and tolerance toadverse environments appear to be at odds or even incompatible with highinternal damping. Viscoelastic materials may show high dampingcapabilities but may be easily contaminated by their environment andusually must be applied as thick coatings since they unfortunately haveinsufficient strength properties. Thus the optimization of a dampingtreatment typically requires not only the proper choice of a dampingmaterial, but an understanding of the effects of the geometry of thedamping treatment and the modal characteristics of the structure beingdamped.

Turbine components which might operate at high temperatures (e.g., up to2500° F.), and/or corrosive/erosive environments, and/or undercentrifugal loads must transition through structural resonanceconditions to reach their operating envelope. Currently, there are noavailable adequate damping treatments which survive the turbineenvironment and do not sacrifice component integrity. U.S. Pat. No.5,775,049 and U.S. Pat. No. 5,924,261 report Lodengraf materials withlow sound speed to damp structural vibration and noise in advanced shipcabinets and electronics enclosures which are filled with granularmaterials like low density polyethylene beads, or lead shots which arenot suitable for gas turbines. U.S. Pat. No. 4,380,544 reports a dampingcomposite where a high damping metal surface layer is deposited on allsides of a poor damping base metal. Examples given are also not suitablefor the harsh turbine environments. For example, high dampingferromagnetic alloys or magnetoelastic damping alloys (12Cr steel orWestinghouse's NIVCO10) are prone to fatigue cracking at 600° C. (1100°F.) due to precipitation of brittle intermetallic phases. Moreover,combining metallic base material and high damping surface layer is notideal where there are large differences in their chemical and physicalproperties where the intended properties may be negatively affected dueto metallurgical events (e.g. diffusional and kinetic processes) duringoperation. Thus, there may exist a need for good damping properties ofsurface architectures designed with good mechanical, thermal, andchemical strength.

In certain embodiments, there may be materials (and processes for themanufacture thereof) that possess high material damping under alloperating conditions, that have good strength over the entire range ofmechanical and thermal stresses, and that facilitate a wide range ofconstruction and/or design of the components.

BRIEF DESCRIPTION OF THE INVENTION

In an aspect, at least one embodiment generally relates to a gas turbineor turbine component partially or fully coated with a damping surfacelayer. The damping surface layer has a thickness between 0.1 and 2000microns and is capable of dissipating vibration or modifying a resonancefrequency of the gas turbine or turbine component at ambient roomtemperatures including operational temperatures greater than 500° F.,and the damping surface layer comprises at least one of (a) at least twolayers comprising a first layer of at least one hard material and asecond layer comprising at least one soft material, (b) a compositecomprising a nickel alloy with a heat softenable chemistry, (c) afine-grained nickel-based superalloy, or (d) a porous metallic coating,a porous metallic and ceramic coating, or a ceramic coating.

In a certain aspect, at least one embodiment generally relates to amethod of making the gas turbine or turbine component partially or fullycoated with a damping surface layer. The method may comprise depositinga layer on a surface of the gas turbine or turbine component usingcathodic arc deposition, pulsed electron beam physical vapor deposition,slurry deposition, electrolytic deposition, sol-gel deposition,spinning, thermal spray deposition such as high velocity oxygen fuel,vacuum plasma spray, or an air plasma spray.

In an aspect, at least one embodiment generally relates to a gas turbineor turbine component partially or fully coated with a damping surfacelayer. The damping surface layer has a thickness between 0.1 and 2000microns and is capable of dissipating vibration or modifying a resonancefrequency of the gas turbine or turbine component at operationaltemperatures greater than 500° F. The damping surface layer comprises atleast one of (a) Ti and AlTiN, (b) Cr and CrN, (c) TiN and Ti, (d)MCrAlY and a glass powder, where M comprises Ni, Co, or Fe, (e) ananograined nickel-based superalloy, (f) a porous zirconium oxide, (g) acracked zirconium oxide optionally with MCrAlY, (h) a porous MCrAlY, ora mixture thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an example of an airfoil having damped vibrationalcharacteristics in accordance with an embodiment of the presentinvention.

FIG. 2 is an illustration of an example of a coating's metallurgicalcross section in accordance with an embodiment of the present invention.

FIG. 3 is an illustration of another example of a coating'smetallurgical cross-section in accordance with an embodiment of thepresent invention.

FIG. 4 is an illustration of a third example of a coating'smetallurgical cross-section in accordance with an embodiment of thepresent invention.

FIG. 5 is an illustration of a fourth example of a coating'smetallurgical cross-section in accordance with an embodiment of thepresent invention.

FIG. 6 compares the amount of damping provided by each surface layerwith respect to untreated base plate under representative operatingconditions in accordance with certain embodiments of the presentinvention.

FIG. 7 compares the amount of damping provided by each surface layerwith respect to untreated base plate under representative operatingconditions in accordance with certain embodiments of the presentinvention.

FIG. 8 compares the amount of damping provided by each surface layerwith respect to untreated base plate under representative operatingconditions in accordance with certain embodiments of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Several types of damping materials may exist. Natural composites (suchas Fe—C—Si and Al—Zn alloys) may use a damping mechanism relating toviscous or plastic flow across phase boundaries between the matrix andthe second phase. Ferromagnetic alloys (such as Fe, Co, and Ni, Fe—Cr,Fe—Cr—Al, Co—Ni—Ti, and Co—Ni—Fe) may use a damping mechanism relatingto magneto-mechanical static hysteresis due to irreversible movement offerromagnetic domain-walls. Alloys based on dislocation damping (such asMg, Mg-0.6% Zr, Mg-Mg2Ni) may use a damping mechanism relating to statichysteresis due to the movement of dislocation loops, breaking away frompinning points. Alloys with movable twin or phase boundaries (such asMn—Cu, Mn—Cu—Al, Cu—Zn—Al, Cu—Al—Ni, Ti—Ni, and NiTi—Co) may use adamping mechanism relating to the movement of twin boundaries,martensite-martensite boundaries, and boundaries between martensite andthe matrix-phase.

In general, the diversity and ambiguity of damping units hasconsiderably complicated collecting, checking and correlating test data.Element parameters, system parameters, and material parameters can bethe measures of damping. Element parameters depend not only upon thematerial but also on the size and shape of the test specimen, as well ason the stress distribution brought about by the method of loading. Thiscategory of parameters may include the equivalent stiffness and viscousdamping constant. System parameters depend upon the various elementstaking part of the system as a whole. Many characteristics of avibrating system, including natural frequency, damping ratio, qualityfactor and logarithmic decrement may be classified within this category.Material parameters may depend only upon the composition and treatmentof the material and are independent of the dimensions of the consideredtest element.

A useful material parameter may be the dimensionless loss factor. Theloss factor of a uniform material may be defined as the ratio of theenergy dissipated during one cycle of simple harmonic stress (withoutany pre-stress) to the maximal strain energy stored in the materialduring the cycle. A higher value of a loss factor may be desired for agood damping surface layer with respect to the untreated base material.

In the past, cast iron has been regarded as the structural material withthe highest internal damping. The actual loss factor of some specialcast irons can be as high as 3%, but is still far too small to improvesignificantly the overall damping of built up structures. For linearmechanisms, loss factors may be independent of stress amplitude and aregenerally found to be dependent on frequency and temperature. Inaddition to desired high loss factor for the surface damping layer, ahigher elastic modulus of the surface layer may be needed for the layerto take on the vibrational energy with respect to the base material.

To prevent turbine failures due to component vibration, the excitedresonant response should be attenuated to an acceptable level. Vibrationsuppression may entail applying a free layer damper (i.e., addition of asurface functional layer (such as coatings) with the right material andmicrostructural features to dissipate vibrational energy) to thecomponent subjected to vibration. The size and the planned operation ofthe turbine may also affect component vibration characteristics whichcan cause reduced fatigue life.

In certain embodiments, this invention involves the application of asurface layer (0.1-2000 microns (and all subranges therebetween),preferably 0.25-500 microns (and all subranges therebetween), and morepreferably 1-100 microns (and all subranges therebetween) thick orthickness much less than component wall thickness) with the rightmicrostructures to absorb and dissipate vibration or modify theresonance frequencies of a vibrating component. The damping surfacelayers may be applied partially or fully on the airfoil surfaces (orother surfaces within a turbine).

One or two same or different materials in the form of a thin coatinglayer may be applied in layers varying in thickness or applicationprocess. And the coatings may be applied to any vibrating component inany machine. For example, coatings applied to airfoils particular to acompressor or turbine section of a gas turbine may be applied tocomponents in the combustor section as well.

Surface structures for turbine components, for example, gas turbinecomponents, are disclosed which provide vibration damping at roomtemperature and above by absorbing vibration of the components and/oraltering resonance frequencies of the components. These components(which may be referred to base materials) may be ferrous alloys, steels,superalloys, and titanium alloys, ceramic matrix composites (CMCs), etc.The vibration damping may increase fatigue lives of the components, forexample, airfoils, compared to undamped components. Such surfacestructures may similarly be utilized to provide other forms of damping,for example, sound damping.

FIG. 1 schematically illustrates a gas turbine component, for example anairfoil 10 with enhanced vibration damping. The airfoil 10 includes anairfoil substrate 12 and a surface structure 14 applied to the airfoilsubstrate 12. Surface structure 14 may contain one or more surfacelayers with varying properties. The surface structure 14 providesvibration damping when applied to the airfoil substrate 12. Embodimentsof vibration damping surface structures 14 may affect changes inchemical, structural, and/or mechanical properties of at least onecomponent of the surface structure 14 to provide the vibration dampingcharacteristics at temperatures involved in the operation of a turbine.

Vibration damping treatments for low- to mid-temperature applications(e.g., less than 400° F.) may primarily consist of viscoelasticpolymeric materials (VEM) with low modulus and high loss factor. VEMsmay work when the treatment thickness is significantly greater than thebase material thickness. It is believed that no successful highertemperature damping treatments have been reported for turbineapplications. At elevated temperatures, pressures, and/or centrifugalloading conditions, there may be a harsh environment requiring surfacelayers to simultaneously dampen vibration and survive operatingconditions.

For gas turbine applications (for example, compustor and/or turbine),the requirements for surface layers are modified for survival up to2000° F. at thicknesses much less than the base material thickness.Materials for good damping may require simultaneous high modulus andhigh loss factor requirements, driving towards combination of metallicand/or ceramic compositions with inherent or engineered hysteresis.Certain embodiments of this invention generally relate to hightemperature (e.g., 1400° F.) capable, thin, and effective vibrationdamping layers (metallic, ceramic, or composite), as metallurgical crosssections are illustrated in FIGS. 2, 3, 4, and 5. Testing was conductedon treated and untreated base flat plates and results are reported inFIGS. 6-8.

Certain aspects of the present invention included selecting candidatesurface layer materials and microstructures suitable for 1400° F.maximum operation (e.g. damping in addition to oxidation, erosion, andcorrosion resistance), applying these coatings on stainless steel andnickel substrate plates for performance screening as compared to theuncoated plates. Loss factor (material property) and the modulus datamay be determined as a function of temperature, strain level, and strainstate for different modes of vibration.

A significant increase in treated substrate-metal material damping atelevated temperatures may be obtained through processing sequential,thin layers of hard and soft materials, composites of nickel alloys withheat softenable chemistries, fine grained nickel based superalloys,and/or porous metallic and/or ceramic coatings. Each system was found tosignificantly improve base material damping when compared to untreated,bare material. Surface layer microstructures and architectures arerepresented in FIGS. 2-5. In certain embodiments, the present inventionmay relate to the use of one or more of these layers together to tailorto desired properties.

Various alloys may be used in exemplary embodiments of the presentinvention. These alloys may be suitable for exposure to temperatures ator greater than 1400° F. These surface layers were applied to AISI304stainless steel and also nickel based superalloy (GTD111 and GTD444)substrate plates using various methods. It is believed that the dampingproperties may be optimized by systematically varying these surfacelayer materials and process parameters.

In various exemplary embodiments, thin (microns or submicrons thick)individual layers of soft and hard materials are sequentially depositedonto AISI304 or GTD111 plates in vacuum. The interfaces betweendifferent layers of metal (soft)/ceramic (hard) layers may act asvibration dissipating boundaries. Surface layers less than total 4 milsthick (100 microns) CrN/Cr, TiAlN/Ti, and TiN/Ti, TiAlCrSiN/Cr,NiAlCrSiN/NiCr architectures (the layer thicknesses can be varied aswell) processed, but not limited to, using cathodic arc or ion plasmamethods may be effective in vibration damping. Suitable coatings may besupplied by NorthEast Coating Technologies, Maine. Of course, dependingon temperature requirements, the oxidation resistance of the surfacelayers can be improved by adding alloying elements to the compositionsabove, or using completely different chemistries with alternatingmechanical properties. An exemplary cross-section is shown in FIG. 2.

In various exemplary embodiments, oxidation resistant metallic orceramic powders are mixed with heat softenable particles such as glass,then thermally sprayed onto the AISI304 and GTD111 plates to form acoating by High Velocity Oxygen Fuel (HVOF) process. Glasses may beamorphous oxides and may typically show a gradual softening fromamorphous solid to liquid phase through a transition temperature. At thetemperatures of interest, the viscosity of the glass is reduced as thetemperature is increased and the glass composition selected and/or themany glass/metal interfaces keep absorbing vibration, even at or greaterthan 1400° F. In certain embodiments, SM4198 powder (MCrAlY, where M isNi, Cu, and/or Fe) (from Sulzer Metco) is mixed and thermally sprayedwith 10%, 30%, or 50% Spheriglass 3000E, or Spheriglass 3000 and Q-Cel6070 (all from PQ Corporation) to 2-80 mil thickness. As the amount ofglassy phase in the metal matrix increases, the damping capability mayalso increase. An exemplary cross-section is shown in FIG. 3. It wasalso found that the amount of damping at temperature can be tuned withthe type of glass used.

In various exemplary embodiments, a porous or intentionally verticallycracked zirconium oxide may be deposited by atmospheric (air) plasmaspraying (APS) over a metallic coating (for example, Sulzer Metco'sSM4198) deposited by HVOF to a total thickness of 5-80 mils. This poroussurface layer can also be sandwiched in between these HVOF metalliclayers which also provide adhesion and grades thermal expansion of basematerial to the to ceramic surface layer. Metallic or ceramicmicroballoons (e.g. hollow spheres) can also be used to create the poresin metallic or ceramic matrices; or a metallic or ceramic open cell foammaterial (such as from Porvair, Inc.) can be used as a damping surfacelayer. The combination of these coating microstructures may also providegood results. It is also conceived that these microstructures with poresand intentional cracks can be filled with heat softenable phases toattain desired level of damping. Exemplary cross-sections are shown inFIG. 4.

In various exemplary embodiments, ultra-fine grained (sub-micronboundaries containing pinning particles) and oxidation and corrosionresistant metallic powders (such as nickel-based superalloy Rene108 orRene104) may be deposited. These surface layers may be formed bythermally spraying (such as by HVOF) nickel based powders which werecryomilled (mechanically milled in liquid nitrogen) before deposition.Mechanical milling may impart sub-grains (at least 30 times smallergrains) in powder particles which also contain very small (3-5nanometers) dispersoids containing Fe, N, and/or O. These coatings mayalso be effective in vibration damping, possibly due to the very manygrain boundaries and fine, dispersions absorbing and dissipatingvibration. An exemplary cross section is shown in FIG. 5.

It is also conceived that these four general types of good hightemperature damping surface layers may be used together in anycombination to adjust or modify desired damping characteristics.

The following table (Table 1) illustrates various exemplary,non-limiting embodiments:

TABLE 1 Various exemplary embodiments of coatings within certain aspectsof the present invention. Application Starting Method/Process PreferredExample No. materials Composition Description Thickness 1 Ni alloy Full10% Glass MCrAlY (where 2-80 mils powder and Mix, 30% mix, M is Ni, Co,glass powder sandwich, 50% or a mixture mixture glass thereof) is mixedwith glass and HVOF processed. Mixture amounts, type of glass, layeringarchitectures can be varied to tune damping. 2 intentionally zirconia +HVOF bond 10-80 mils cracked MCrAlY (GT33) coat + APS top ceramic topcoat coat on metallic coating on base material 3 porous GT33/porous HVOFGT33 + ceramic and zirconia/GT33 Porous TBC+ metal layers HVOF GT33(sandwich) 4 intentionally 7%, 14% EB PVD 2-10 mils cracked zirconiaceramic coating 5 composite MCrAlY + BN; APS (GT50 3-80 mils coatingMCrAlY + ZrO₂ + metallic), BN + MCrAlY GT50 sandwiched GT33; APS (GT60ceramic), GT60 sandwiched GT33 6 multiple 1Ti + 4AlTiN; Ion plasma0.01-2 mils microlayers 0.5 Ti + 1 (cathodic arc) AlTiN; 4.9 μm CrN + 1μm Cr; 1.6 μm CrN + 1.1 μm Cr 7 nanograined Rene108, HVOF of 2-80 milsmetallic Rene104 cryomilled powder

Deposition of multilayered coatings by cathodic arc is reported in Y.-Y.Chang et al., Surface & Coatings Technology 200 (2005) 1702-1708. Seventypes of surface layers and corresponding compositions are reported inTable 1. These may be modified to improve high temperature propertiesbeyond 1400° F., e.g., as long as the thermal expansion coefficients canbe matched with the surface layers and the base material. Also, anoptional layer of protective metallic, ceramic, or composite coating canbe deposited onto these vibration damping surface layers or anycombination of these seven types of damping layers can be applied on avibrating gas turbine component (compressor, combustor, or turbinesections).

FIGS. 6-8 summarize the vibration damping testing results from thesurface layers described in Table 1. Figure of merit, Q, which takesinto account the relative surface layer and base material Young'smoduli, loss factor, and thickness is plotted for room temperature up to1400° F. as a function of applied stress for second flex (2F) and firsttorsion (1T) modes. Figure of merit is determined according to thefollowing formula:

$\Delta \; {\left. Q \right.\sim\frac{E_{S}\eta_{S}}{E_{O}\eta_{O}}}\frac{h_{S}}{h_{O}}$

where Q is the Figure of merit, E_(s) is the Young's modulus of thesurface layer (i.e., the ability to take vibrational energy), E_(o) isthe Young's modulus of the untreated base layer, η represents a lossfactor (i.e., the ability to dissipate energy), and h is thickness.

All surface treatments described in Table 1 showed at least 50% dampingimprovement over untreated baseline material in all modes measured.Laser vibrometry measurements were done in high temperature oven wherebase materials were in the form of flat plates and were fixtured on aspring loaded floating table to make sure any fixture damping waseliminated.

FIGS. 2-5 schematically illustrate various structures for surfacestructure 14. As illustrated in FIG. 2, consecutive hard and soft layers22 may be deposited on substrate 12 and may also be treated with aprotective layer 40 depending on the operating conditions. In thisexample, alternating layers of 0.5 microns thick metallic Ti and 1micron thick titanium aluminum nitride materials were applied byNortheast Coating Technologies, Kennebunk, Me. using their commercialPVD coater. Alternating layers of Titanium and AlTiN were applied to atotal film thickness of 7 microns.

As illustrated in FIG. 3, heat, electrical or magnetic field, orpressure softenable material 16 may be incorporated into oxidationresistant metallic or ceramic material 18 and the resulting compositemay be deposited on substrate 12 and then may also be treated with aprotective layer 40 depending on the operating conditions. In thisexample, −140 mesh MCrAlY powder (SM4198) was mixed with −90 micron Qcel6070 powder from The PQ Corporation, Conshohocken, Pa. After 60 gritAl₂O₃ grit blasting the substrate with 60 psi pressure, the powder mixwas deposited onto the substrates using DJ2600 gun at 600 mm/s speed and68 schf hydrogen fuel flow rate.

The glass particle size may range, for example, between 5 and 15 micronsat 10%, between 25 to 45 microns at 50%, or between 65 and 90 microns at90%.

As illustrated in FIG. 4 a, pores 24 may be incorporated in the surfacestructure 14, as can open cell or hollow sphere foams 20, as illustratedin FIG. 4 b, or microballoons 26, as illustrated in FIG. 4 c, orperiodic vertical cracks 28, as illustrated in FIG. 4 d. Pores 24 mayinclude micropores having diameters of 0.5-100 microns, nanopores ofdiameters of 15-500 nm, and/or macropores having diameters greater than100 microns. Pores can be inherent to the plasma spray processing of204NS-G commercial zirconia powder using Argon at 79.8 SCFH rates as theprimary gas. Pores can also be generated using sacrificial polymerparticles during thermal spray processing to create the pores afterpolymer burn off step. Foams 20 may include metal/ceramic open cellfoams (such as ones provided by Selee Corporation, Hendersonville,N.C.), hollow-sphere foams (such as those from Fraunhofer Corporation,Germany), and/or metal-infiltrated ceramic foams. Microballoons 26 maybe a powder comprising clusters of glass spheres or hollow particles.

Additionally, as shown in FIG. 5, surface structure 14 may be applied tothe airfoil substrate 12 using fine grained (grain boundaries 32) anddispersoid 34 filled powder particles. Cryomilling in liquid nitrogencan be used to impart dispersoids in the powder particle grains whichcould form a damping coating after HVOF spraying using 500 mm/s gunspeed and oxygen (170 psi, 32 FMR) and hydrogen (140 psi, 70 FMR) as thefuel.

The damping surface structures 14 described above may be applied to thedesired gas turbine components by a number of appropriate methodsdepending on the substrate material, desired surface layer material, andmicrostructure. These methods may include cathodic arc, pulsed electronbeam physical vapor deposition (EB-PVD), slurry deposition, electrolyticdeposition, sol-gel deposition, spinning, thermal spray deposition suchas high velocity oxy-fuel (HVOF), vacuum plasma spray (VPS) and airplasma spray (APS). It is to be appreciated, however that other methodsof coating application may be utilized within the scope of thisinvention. The surface structures may be applied to the desiredcomponent surfaces in their entirety or applied only to areas of thecomponent to be damped.

In at least certain embodiments, the damping surface layer comprises aplurality of layers, wherein the plurality of layers comprises at leastone hard layer comprising a ceramic layer and comprises at least onesoft layer comprising a metal alloy. In at least certain embodiments,there are a plurality of layers comprising a layer of titanium, nickel,cobalt, iron, chromium, silicon, germanium, platinum, palladium, and/orruthenium and comprises a layer of aluminum, titanium, nickel, chromium,iron, platinum, palladium, and/or ruthenium.

In at least certain embodiments, the damping surface layer includes acomposite with a softenable phase, wherein the composite comprises anoxidation resistant metallic material, and wherein the softenable phasecomprises a silica-based glass. In at least certain embodiments, thecomposite comprises nickel-chromium-aluminum-yttrium,cobalt-chromium-aluminum-yttrium, or nickel-chromium-aluminum-yttriumand optionally comprises platinum, palladium, ruthenium, or germanium.

In at least certain embodiments, the damping surface layer comprises aporous ceramic or metallic layer. In at least certain embodiments, thedamping surface layer comprises a metal oxide. In at least certainembodiments, the damping surface layer comprises a zirconium oxideand/or aluminum oxide.

In at least certain embodiments, the damping surface layer comprises acryomilled nickel-based, cobalt-based, or iron-based superalloy.

In at least certain embodiments, the gas turbine or turbine component ofclaim 1, wherein the damping surface layer comprises chromium andchromium-nitrogen.

All disclosed and claimed numerical amounts and ranges are approximateand include at least some degree of approximation.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiment, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1. A gas turbine or turbine component partially or fully coated with adamping surface layer, wherein the damping surface layer has a thicknessbetween 0.1 and 2000 microns and is capable of dissipating vibration ormodifying a resonance frequency of the gas turbine or turbine componentat ambient room temperatures including operational temperatures greaterthan 500° F., and wherein the damping surface layer comprises at leastone of (a) at least two layers comprising a first layer of at least onehard material and a second layer comprising at least one soft material,(b) a composite comprising a nickel alloy with a heat softenablechemistry, (c) a fine-grained nickel-based superalloy, or (d) a porousmetallic coating, a porous metallic and ceramic coating, or a ceramiccoating.
 2. The gas turbine or turbine component of claim 1, wherein thedamping surface layer comprises a plurality of layers, wherein theplurality of layers comprises at least one hard layer comprising aceramic layer and comprises at least one soft layer comprising a metalalloy.
 3. The gas turbine or turbine component of claim 2, wherein theplurality of layers comprises a layer of titanium, nickel, cobalt, iron,chromium, silicon, germanium, platinum, palladium, and/or ruthenium andcomprises a layer of aluminum, titanium, nickel, chromium, iron,platinum, palladium, and/or ruthenium.
 4. The gas turbine or turbinecomponent of claim 2, wherein the damping surface layer has a thicknessbetween 0.25 and 50 microns.
 5. The gas turbine or turbine component ofclaim 1, wherein the damping surface layer comprises a composite with asoftenable phase, wherein the composite comprises an oxidation resistantmetallic material, and wherein the softenable phase comprises asilica-based glass.
 6. The gas turbine or turbine component of claim 5,wherein the composite comprises nickel-chromium-aluminum-yttrium,cobalt-chromium-aluminum-yttrium, or nickel-chromium-aluminum-yttriumand optionally comprises platinum, palladium, ruthenium, or germanium.7. The gas turbine or turbine component of claim 5, wherein the dampingsurface layer has a thickness between 50 and 2000 microns.
 8. The gasturbine or turbine component of claim 1, wherein the damping surfacelayer comprises a porous ceramic or metallic layer.
 9. The gas turbineor turbine component of claim 8, wherein the damping surface layercomprises a metal oxide.
 10. The gas turbine or turbine component ofclaim 9, wherein the damping surface layer comprises a zirconium oxideand/or aluminum oxide.
 11. The gas turbine or turbine component of claim8, wherein the damping surface layer comprises pores, cell or hollowsphere foams, microballoons, and/or vertical cracks.
 12. The gas turbineor turbine component of claim 1, wherein the damping surface layercomprises dispersoids in powder particle grains.
 13. The gas turbine orturbine component of claim 12, wherein the damping surface layercomprises a cryomilled nickel-based, cobalt-based, or iron-basedsuperalloy.
 14. The gas turbine or turbine component of claim 1, whereinthe damping surface layer comprises chromium and chromium-nitrogen. 15.A method of making the gas turbine or turbine component of claim 1, themethod comprising depositing a layer on a surface of the gas turbine orturbine component using cathodic arc deposition, pulsed electron beamphysical vapor deposition, slurry deposition, electrolytic deposition,sol-gel deposition, spinning, thermal spray deposition such as highvelocity oxygen fuel, vacuum plasma spray, or an air plasma spray. 16.The method of claim 15, wherein the step of depositing a layer comprisessequentially depositing a plurality of layers comprising at least onesoft layer and at least one hard layer cathodic arc or ion plasmadeposition techniques.
 17. The method of claim 15, wherein the step ofdepositing a layer comprises: mixing a heat softenable particle with atransition phase with an oxidation resistant metallic and/or ceramicpowder to form a mixture; and spraying the mixture onto the gas turbineor turbine component using a high velocity oxygen fuel process.
 18. Agas turbine or turbine component partially or fully coated with adamping surface layer, wherein the damping surface layer has a thicknessbetween 0.1 and 2000 microns and is capable of dissipating vibration ormodifying a resonance frequency of the gas turbine or turbine componentat operational temperatures greater than 500° F., and wherein thedamping surface layer comprises at least one of (a) Ti and AlTiN, (b) Crand CrN, (c) TiN and Ti, (d) MCrAlY and a glass powder, where Mcomprises Ni, Co, or Fe, (e) a nanograined nickel-based superalloy, (f)a porous zirconium oxide, (g) a cracked zirconium oxide optionally withMCrAlY, (h) a porous MCrAlY, or a mixture thereof.